It is often necessary in fluid process piping systems to divert the flow of fluid from one stream to another. Such can be conventionally accomplished using a diaphragm-type diverter valve, i.e. a three-way valve. Valves of this type divert the flow of fluids from a single inlet port to one or the other of two outlet ports by closing a diaphragm against an edge or weir of a partition within the valve housing, thus prohibiting fluid flow to the one port and accommodating flow to the other port. An example of this type of valve is disclosed in U.S. Pat. No. 5,427,150, entitled "HOUSING FOR A DIVERTER VALVE" issued to Richard A. Skaer, on Jun. 27, 1995, the entire disclosure of which is hereby incorporated by reference as if being set forth in its entirety herein.
With reference to FIGS. 1 and 2, there is shown a diverter valve housing 10 according to the teachings of the '150 patent comprising a body having a flat base 12, front and rear walls 14 and 16 respectively, and side walls 18 and 20, all which rise from the base 12. Front wall 14 has an inlet port 22 formed therein which opens into a chamber 24 formed within the housing 10. The chamber 24 has a curved drainage channel 26 at the bottom, and is subdivided by a partition 28. The rear wall 16 has a pair of outlet ports 30 and 32 formed therein which also respectively open into the chamber 24 in the housing 10. The partition 28 includes a tapered limb with walls between the ports 30 and 32. Consequently, the partition 28 forms the chamber 24 into a first compartment 34, into which the port 22 opens, a second compartment 36 into which port 30 opens, and a third compartment 38 into which port 32 opens (see FIG. 2).
Side walls 18 and 20 have openings 40 and 42 formed therein, and the partition 28 has edges 44 and 46 which bisect the openings 40 and 42. Additionally, the edges 44 and 46 define weirs which comprise recesses 48 and 50 against which diaphragms set, or from which diaphragms remove, to prohibit or to permit fluid flow through one or the other of the ports 30 and 32.
Referring now also to FIG. 3, there is illustrated the housing 10 of FIGS. 1 and 2 cross-sectioned through the center of the openings 40 and 42. In addition, FIG. 3 shows the diaphragms 52 and 54, with respective handwheel-actuated compressors 56 and 58 attached thereto. Diaphragm 52 is closed against weir or edge 44, and diaphragm 54 is removed from weir or edge 46. As a result, and as is conventionally understood, fluid flow from port 22 to port 30 is prohibited, and flow is accommodated from port 22 to port 32.
To insure against the trapping of fluids in the housing 10, when the latter is horizontally disposed, as part of a diverter valve in a piping system, the '150 invention provides a horizontal drainage plane. The lowermost portions of the ports 22, 30 and 32, the openings 40 and 42, and the weirs or edges 44 and 46 are contiguous with, and fair into, the drainage channel 26. There is offered, in the housing 10, then, no pocket or recess in which a residual fluid can pool. In addition, the side walls 18 and 20, as shown are inclined from the vertical, defining the front and rear walls 14 and 16 substantially triangular. It has been found that by inclining the walls 18 and 20, with an angle there between of from forty to eighty degrees of arc, the full drainage of liquid through the housing 10 is greatly facilitated. The horizontal drainage plane of the housing 10 is represented by the flow lines 120 shown in FIGS. 1 and 2.
As has been discovered, when a diverter valve of this type is installed in fluid process piping systems in a vertical disposition and when fluid flow is halted, the housing 10 typically exhibits a sufficiently thorough drainage there through for many processes. However, there are piping systems which require the diverter valve exhibit an extraordinarily high amount of drainage as even a small amount of residual fluid remaining in the housing will be conducted out with a next flow of fluid, when the valve is operated again, thus contaminating the successive flow of fluid. This represents a significant problem in pharmaceutical and biotech process applications for example, where cleanliness and sterility are vital.
It is an object of the present invention to overcome this problem with a valve that exhibits this extraordinarily high amount of drainage whether it is installed in a horizontal or vertical position.